Apparatus for closing the open end of a bag



Sept. 25, 1962 B. MAESTRI 5 APPARATUS FOR CLOSING THE OPEN END OF A BAG Filed June 1, 1959 2 Sheets-Sheet 1 4 fr INVENTOR. V Bran PIQQSPH BY HU S. .C'fn'ku- Sept. 25, 1962 B. MAESTRI 3,055,010

APPARATUS FOR CLOSING THE OPEN END OF A BAG Filed June 1, 1959 2 Sheets-Sheet 2 IN VENTOR.

rates This invention generally relates to the closing or sealing of bags or bag type containers and, more particularly, to new and advantageous means for safely and readily applying a band or strip to, and wrapping it about, the neck of a bag made from pliable plastic sheet material to close and seal the bag.

It is well known in the art that plastic bag containers, e.g., the extensively used plastic bags designed for wrapping food and other perishable goods, the mouth portion of which may be compressed to form a neck, may be easily tied by causing a small metallic band or strip to be curled about the neck in the manner of a fillet. Some problems are, however, involved if a positive sealing of the bag or container is desired, in particular if for best protection of the goods a vacuum is produced inside of the container.

Other problems arise in the manufacture of strip means which, on the one hand, should be inexpensive and, on the other hand, should not cut or otheiwise damage the thin plastic sheet material of the bag about which the strip is tightly curled.

One of the most common difficulties encountered in connection with such tying means is caused by the fact that the effective diameter of the compressed neck of bags may noticeably vary according to the mode in which the sheet material folds itself. If strips which are too long have their end portions positioned in abutting relationship, they cannot be tightly wrapped about the neck. A strip which is too short cannot completely encircle the neck and, therefore, the sealing will be insuificient.

In addition, when such metallic strip is curled and squeezed about the neck in a conventional mode, some scraping occurs between the metallic strip and the bag material. To prevent such scraping and resulting cuts or ruptures of the sheet material, the use of costly roundcornered bands of smooth surface has often been resorted It is, therefore, an object of this invention to provide apparatus for applying and tying a metallic strip or band about the neck of a plastic bag in an improved manner which will avoid the difficulties encountered in the past.

A further object of the invention is to provide apparatus comprising material cutting means adapted to successively cut off bands or strips from sheet material; ompressing means adapted to prepare the bag necks for t ving; and band curling and squeezing means for causing t 1e bands to be helically wound about and firmly secured t the compressed necks.

i Other objects and advantages of the invention will Hecome apparent as the description proceeds.

The invention will be best understood from the following detailed description of a preferred form thereof, when taking in conjunction with the accompanying drawings, wherein:

FIG. 1 shows, in plan view and on an enlarged scale, a metallic band shaped for helical wrapping thereof about a compressed neck of a plastic bag;

FIG. 2 is a perspective illustration of the band of FIG. 1 after helical curling thereof;

FIG. 3 illustrates how such band, previously bent in a *atent C-shape, may be placed about the neck portion of a bag in the first step of a sealing procedure;

FIG. 4 is a plan view of a metal sheet from which ice a plufiality of bands of the type shown in FIG. 1 may be cut 0 FIG. 5 is a perspective exploded view including the material of FIG. 4 previously bent in a manner similar to that shown in FIG. 3; an individual, cut-off band; and the head portions of tools designed for cutting, curling and squeezing the bands about the necks to be sealed;

FIGS. 6 and 7 are front views of the head portions of the tools of FIG. 5;

FIG. 8 illustrates components of the device of the invention as positioned during the first step of the operation, the device being shown in a horizontal sectional view taken in plane 8-8 of FIG. 11;

FIG. 9 shows the same components as positioned during the second step of the operation;

FIG. 10 illustrates the same components as positioned during the last step of the operation, the parts being shown in a sectional view taken in plane 1010 of FIG. 12;

FIG. 11 illustrates significant mechanism of the bag sealing device according to the invention, in a vertical sectional view taken in plane 11-11 of FIG. 8; and

FIG. 12 illustrates the mechanism of FIG. 11 after completion of the bag sealing operation, in a vertical sectional View taken in the plane l2l2 of FIG. 10.

Referring now to the drawings, wherein like reference numerals refer to like parts throughout the several figures, various ancillary components and mechanisms of standard type have been omitted therefrom.

In accordance with the objects of the invention, my device serves for sealing the previously manually compressed neck portion 20 (FIGS. 3, 8, 9, l0 and 12) of a bag 21 produced from a pliable, plastic sheet; for example, a bag of the type used for wrapping and protecting food and other goods on sale. Such scaling is performed by means of a metallic band or strip 22, preferably but not necessarily made of sheet aluminum and having end portions 23 and 24 adapted to be curled about the neck 20 of the bag so as to encircle the same.

According to the invention, the band is bent in a manner such that it is caused to curl itself in a helical shape, as shown in FIG. 2, wherein the band is in the form of a ringlet extending through more than 360 about an imaginary cylinder. When viewed from above, the end portions 23 and 24 overlap each other, but they are disposed at different levels whereby such overlapping portions may lie on the surface of the same imaginary cylinder.

It will, therefore, be clear that I provide for amply encircling the neck of the bag by using bands longer than actually required to encompass the neck of the bag.

As it may be readily understood from a consideration of FIGS. 1 and 4, the metal sheet from which the bands or strips 22 are formed is previously shaped to facilitate the helical bending and curling about the neck. In FIGS. 4 and 5, the line P--P indicates the axis of the imaginary cylinder defining the curvature of the curled band and it is shown that the end portions 23 and 24 are arranged to form an angle A (FIG. 4) exceeding with the axis P-P.

Preferably, the material is manufactured by cutting a flat metal sheet in a die so that it will have the shape illustrated in plan view in FIG. 4, wherein the material generally indicated at 26 is shaped for having a plurality of bands 22 successively cut therefrom by dividing the material 26 along the dotted lines 25 which pass through central connecting portions extending transversely of the bands to be cut. The arrow 25 indicates the line along which the material has been cut at one of its ends.

For feeding the material to the bag sealing device of the invention, it may be prepared in a bent shape, as shown in FIG. 5, wherein the bent material is generally indicated at 26a. Thus, the bands 22 cut from the material will have the C-shape illustrated in FIGS. 3, 5, 8 and 9, to facilitate the further bending, curling and squeezing thereof about the necks of the bags to be sealed.

The said helical curling of the bands is performed by co-operating, elongated tools generally indicated at 29 and 39. Tool 29, provided with a sharpened cutting edge 28, is caused to move from a retracted position in the direction B (FIGS. 5, l and 12) to cut the material 26a along the line 25" for detaching one band 22 therefrom and then pushing the hand against the oppositely located tool 38 which acts as a bending anvil and cooperates with tool 29. As shown in the drawings, the anvil tool 36 has a V -shaped end or clamping face.

The helical shaping of the bent band is achieved by the provision of guide means in the end or head portions of the tools. Such guide means may consist of inclined side portions 31 (FIGS. 5 and 6) on the head of tool 29 and of likewise inclined recesses 32 in the head portion of the anvil tool 30 (FIGS. 5 and 7), whereby the end portions 23 and 24 of band 22 are caused to slide on tool 30 in the recesses 32 thereof and are compelled to curl obliquely in the helical form shown in FIG. 2.

The tools 29 and 3d are slidably supported in a horizontal channel 50 of a support means or guide assembly 35 (FIGS. 8 to 12) mounted on the frame of the device. The guide assembly 35 is provided with a recess or cutout 33 which is shaped as shown in FIG. 8 and has a lateral entrance opening as well as a semicircular end portion, and wherein the operator may set the manually com.- pressed neck of the bag to be sealed. The neck is then mechanically compressed by the device so that it is compact and stiff, and this is done prior to the application thereto and squeezing thereabout of the bandv Such prior pressing of the neck, which constitutes an important step and will protect the bag material from cutting and other damages as might be caused by contact with the metallic band, is performed by motion, in the direction C (FIGS. 5 and 9), of the anvil tool 30 which urges the neck 20 into the semicircular portion of recess 33, the semicircular portion defining a clamping face. In addition, the upper and lower edge portions of tool 30 are provided with small rims 34 (FIGS. 5 and 7) which the plastic material of neck 26 abuts during the pressing step, leaving the recesses 32 free for the end portions 23 and 24 of the band to enter and curl themselves therein without appreciable scraping of the metal on the plastic material.

The tools 29 and 30 are operated by suitable actuating means (not shown) which are preferably connected to the apparatus at the left side thereof as viewed in FIGS. 8 to 12. A linking rod 36 (FIGS. 11 and 12) is provided to operatively connect tool 30 to the actuating means. The latter may be in the form of any conventional hydraulic or pneumatic source of motion, or of a hand or foot operated mechanism, which will be readily understood by those skilled in the art to which this invention appertains, provided that such actuating means are adapted for causing the anvil tool 30 to reach the position shown in FIG. 9 and also illustrated in FIGS. and 12, wherein the neck is strongly pressed into the recess 33 prior to the time at which the cooperating tool 29 bringsthe band 22 into abutting relationship with the anvil tool The device is further provided with a feeding assembly which may be advantageously constructed in a rather simplified way as illustrated in FIGS. 11 and 12 and generally indicated at 37 therein. A vertical channel 51 (FIGS. 11 and 12) extends transversely of channel 50 and communicates at one of its end therewith in a region spaced from the recess or cutout 33. The channel 51 accommodates a vertically arranged rod 27 which forms a guide means adapted to support the material 26a and to downwardly guide the same so that bands 22 may be successively cut off from the lower end portion of the 4, material by means of tool 29 actuated in the direction of arrow B during each cycle of operation of the device.

Further included in the feeding assembly are means for obtaining a step-by-step downward motion of the material 26a. Such means may include a feeding lever 38 pivotally supported and operated by a vertically reciprocable member 39. The latter is biased downwardly by a spring '40 and during each operating cycle is lowered and lifted in response to the horizontal movements of a cam portion 41 which is integral with tool 29 and acts on a roller 42 provided on the member 39. The feeding assembly 37 is preferably detachably connected to the frame structure of the apparatus and secured thereto by means of a clamping member 43, for example.

The manner in which the device is operated will be readily understood from the foregoing description. During movement of the tools 2% 38 toward each other, the open end of bag 21 extending through the cutout or recess 33 will be compressed between the clamping faces to form a tight neck 26, and a C-shaped band or strip 22 will be fed against the neck and clamped around it in form of a helix with the free end portions 23, 24 of the band or strip overlapping each other in a direction substantially normal to the operating path of the tools 29, 36.

While the invention has been described and shown but in one preferred form of embodiment thereof, it should be noted that the invention is not limited to the details described and illustrated, and that such details should not be taken as restrictive of the invention, as it is obvious that various modifications in design may be resorted to Without departing from the spirit and scope of the invention as defined in the appended claim.

Having thus described the invention, what I claim as new and desire to have protected by Letters Patent is:

Apparatus for closing the open end of a bag of pliable material comprising, in combination, support means formed with a first channel therethrough and with a second channel extending transversely to said first channel and communicating at one end thereof with the latter, said supporting means having a cutout spaced from said one end of said second channel and through which the open end of the bag is adapted to extend, said cutout defining a first clamping face; feeding means for feeding a plurality of substantially C-shaped strips of bendable material integrally connected to each other by connecting portions extending transversely to said strips intermediate the free ends thereof through said second channel into said first channel with the last of said strips abutting against said support means; an elongated t-ool member located in said first channel at one side of said support means and having an end face formed with a cutting edge and being movable from a retracted position located at the side of said second channel distant from said cutout to a clamping position in which said end face is located in the region :of said cutout so that during movement of said elongated tool member from said retracted to said clamping position the connecting pontion between the last and the next before last of said strips is severed and th thus separated strip fed toward said cutout; and an anvil member located in said first channel substantially aligneid with said elongated tool member and having a second substantially V-shaped clamping face extending substantially normal to said elongated tool member and being formed with a pair of grooves having each a bottom face extending substantially parallel to said second clamping face and a pair of side faces substantially normal to said bottom face and at least one of said side faces in each groove being inclined at an obtuse angle to a line substantially normal to the direction of movement of said tool member, said second clamping face being spaced from and facing said first clamping face, said anvil memher being movable in a direction opposite to the direction of movement of said elongated tool member, whereby during movement of said tool and anvil members towards each other an open end of a bag extending through said cutout in said support means will be tightly compressed between said clamping faces into a neck and a C-shaped strip fed against said neck will be tightly clamped about said compressed neck in form of a helix with the free end portions of the strip overlapping each other in direction of said line.

References Cited in the file of this patent UNITED STATES PATENTS Hicks May 16, 1933 Maynard June 19, 1934 Gerke Dec. 9, 194 1 Lindstrom June 29, 1954 Pollock Oct. 26, 1954 

